Blankson Emmanuel R, Klerks Paul L
Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana, USA.
Environ Toxicol Chem. 2016 May;35(5):1123-9. doi: 10.1002/etc.3248. Epub 2016 Feb 11.
The present study investigated the effect of bioturbation by the oligochaete worm Lumbriculus variegatus on the transport and environmental distribution of lead (Pb). Experiments used L. variegatus at densities of 0 ind./m(2), 2093 ind./m(2), and 8372 ind./m(2), in freshwater microcosms with Pb-spiked sediment. At the end of the 14-d experiment, Pb levels in the water column, tissues of L. variegatus, and sediment were determined, and bioturbation was quantified using luminophores. The bioturbation by L. variegatus increased Pb transport from the sediment to the water column. However, it did not significantly affect Pb bioaccumulation by L. variegatus or Pb levels in the sediment. The biodiffusion coefficient (Db) was positively related to worm density, but did not differ between Pb-spiked sediment and uncontaminated sediment. The latter finding suggests that Pb at the 100 μg/g concentration used in the present study did not affect L. variegatus bioturbation. The present study shows that bioturbation can enhance Pb transfer across the sediment-water interface and thus enhance Pb availability to organisms in the water column.
本研究调查了寡毛纲蠕虫颤蚓对铅（Pb）的迁移及环境分布的生物扰动作用。实验在添加了铅的淡水微型生态系统中，以0条/平方米、2093条/平方米和8372条/平方米的密度使用颤蚓。在为期14天的实验结束时，测定了水柱、颤蚓组织和沉积物中的铅含量，并使用发光体对生物扰动进行了量化。颤蚓的生物扰动增加了铅从沉积物到水柱的迁移。然而，它对颤蚓的铅生物积累或沉积物中的铅含量没有显著影响。生物扩散系数（Db）与蠕虫密度呈正相关，但在添加铅的沉积物和未受污染的沉积物之间没有差异。后一发现表明，本研究中使用的浓度为100μg/g的铅不会影响颤蚓的生物扰动。本研究表明，生物扰动可以增强铅在沉积物-水界面的转移，从而提高水柱中生物对铅的可利用性。
